SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0073bc466f14e91e2cc3d786b5e291aa498f93f5a4d7938f56d00bf99f8e7b85' 
  AND token = 'QChL/+BMhvjs0G95VFUyoPnSECLqP8y5TGoS2BsfyLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}